1. Field of the Invention
The present invention relates to a developing apparatus, a process cartridge, and an image forming apparatus, and more particularly, this invention is suitably applied to an image forming apparatus such as a copying machine and a printer that adopt an electrophotographic method, and form an image on a recording medium.
2. Description of the Related Art
When a developer (toner) falls or flies from a developing apparatus or a process cartridge, an image forming apparatus is contaminated by the developer, and thus defective images may occur.
Therefore, there is proposed a fly developer containing portion for receiving falling or flying developers being provided in a conventional image forming apparatus, a developing apparatus or a process cartridge. More specifically, for example, there is proposed a fly developer containing portion provided integrally with a developing blade on the downside thereof. See Japanese Patent Application Laid-Open No. 5-53434. The developer flying from the tip of the developing blade is contained in the fly developer containing portion. It should be noted that the developing blade as described herein forms developer into a thin layer, the developer being supplied from the developer containing portion to a developing roller serving as a developing unit.
In an image forming apparatus, a developing apparatus and a process cartridge as previously described, a developer falling or flying from a photosensitive drum, a developing roller or a developing blade, can be contained in the mid-area of the developing roller in the longitudinal direction. However, due to powder pressure of the developer contained in the mid-area of the developing roller in the longitudinal direction, the contained developer is forced to move or suspended to both ends of the developing roller in the longitudinal direction, and eventually may fall or fly from the both ends of the fly developer containing portion into the image forming apparatus.
Also, the developing apparatus and the process cartridge are adapted to be detachably mountable to the main body of the image forming apparatus. For this reason, due to a shock occurring during detaching or mounting operation of the developing apparatus or the process cartridge by an user, a fly developer contained in the fly developer containing portion may be moved to the both ends of the developing roller in the longitudinal direction, and eventually may fall or fly therefrom.